A057553 Rank of (1,1,...,1) (n 1's) when {0,1,2,...}^n is lexicographically ordered.

1, 5, 16, 56, 203, 749, 2795, 10517, 39832, 151658, 579956, 2225964, 8570330, 33086030, 128028650, 496432760, 1928418395, 7503144365, 29235705215, 114064338335, 445552419545, 1742264571605, 6819546853625, 26717004445325

Offset

1,2

Links

Table of n, a(n) for n=1..24.

Formula

a(n)=C(2n-1, n)+b(n-2)+1, where b=A057552.

Example

For n=3, the ordering starts (0,0,0), (0,0,1), ... and the 15th term is (1,1,1).

Crossrefs

Sequence in context: A120343 A301280 A153366 * A226973 A006217 A281870

Adjacent sequences: A057550 A057551 A057552 * A057554 A057555 A057556

Keyword

nonn

Author

Clark Kimberling, Sep 07 2000

Status

approved